SELF TAPPING SCREW
Self-tapping screws are different to traditional screws as they tap their own threads when screwed into either plastic, wood or metal.
The Slotted or Minus type drive can be said to be outdated but is still quite popular in India as many small and traditional trades are using this. Another reason for the continued
popularity is that many assemblies are still being done manually and workmen have the traditional screw drivers with them.
SLOTTED PAN AS PER DIN 7971
A slotted pan as per DIN 7971 refers to a type of screw that typically has a pan-shaped head and a slotted drive. This standard is governed by the German Institute for Standardization (Deutsches Institut für Normung), which sets specifications for the design and dimensions of various fasteners.
SLOTTED CSK AS PER DIN 7972
The Slotted Countersunk [CSK] self tapping screws are used to provide a flush finish to the assembly. Manufactured as per DIN 7972, these are available in Mild Steel and Stainless Steel grades 304 and 316
USAGE GUIDELINES
- The pilot hole size is very important to achieve a proper installation. Make trials using the guidelines in the product datasheets before mass production. The hole size would be dependent upon the base material strength, base material thickness, pull out strength and ease of installation required.
- Do not overtighten. Use the correct tightening Torque as recommended. See the product datasheets for information. Usage of Torque control drivers is suggested.
- Do NOT use the screws to compensate for any alignment defects by applying more force than required. This will cause un-stability of the connection and unpredictable failure.
- Use the correct countersink tool for CSK screws to achieve a flush fixing.
